Locked-in-mesh-rack-and-pinion mechanism for typewriter



Jan. 15, 1957 J. E. FINCH, SR 2,777,558

LOCKED-INMESHRACKANDPINION MECHANISM FOR TYPEWBITER' 2 Sheets-Sheet 1 Filed Nov. 25, 1955 INVENTORQ A TTOENE) Jan. 15, 1957 J. E. FINCH, SR

LOCKED-IN-MESH-RACK-AND-PINION MECHANISM FOR TYPEWRITER 2 Sheets-Sheet 2 Filed Nov. 25,- 1953 INVENTOR. JOHN E. FINCH,5R

BY V

#QMZB ATTOR/VE) Unite rates Patent LO CKED-lN-MESH-RACK-AND-PINION WCHANISM FGR TYPEWBITER John E. Finch, Sn, Eersey City, N. J.

Application November 25, 1953, Serial No. 394,403 14 Claims. (Cl. 197-96) My invention relates to an improvement in typewriter machines, and more particularly to animproved locked in mesh rack and pinion mechanism for typewriters.

It is an object of my invention to mechanically lock the rack in its proper depth of mesh with the pinion on that type of typewriter which employs a disengaging rack, rather than depending upon a spring or springs to maintain mesh as heretofore, thereby to efiect a smoother carriage movement during typewriting.

Another object of the present invention is to bring about the release of the rack from the lock when the tabulator key or rack release lever is depressed.

Another object of my invention is to assure a more positive and uniform left margin to the writing by preventing either whole or partial rack lift from pinion mesh due to impact on return of the carriage to the left margin stop, whether return be made manually or by power.

Another object of this invention is to assure a more positive and uniform tabulation by dropping the rack into instant locked mesh with the pinion, when the tabulation point has been reached by the carriage.

Another object of this invention is to make possible the use of obliquely cut or various other shapings of rack and pinion teeth, with the object of reducing carriage vibration, not presently feasible with a disengaging rack, due to the likelihood of disengagement skip.

Still another object of my invention is to greatly reduce wear on the teeth of a rack and pinion in the typewriter.

Other objects and features of this invention will become apparent from the accompanying detailed description taken in conjunction with my accompanying drawings wherein:

Fig. 1 is an end or side view of a typewriter machine taken on line 1-1 of Fig. 2 and embodying a preferred form of my invention;

Fig. 2 is a broken away top plan view of a typewriter machine with a carriage mechanism embodying my invention;

Fig. 3 is a section of a detail taken on line 33 of Fig. 2;

Fig. 4 is a section taken on line 44 of Fig. 2;

Fig. 5 is a fragmental vertical elevation taken on line 55 of Fig. 2;

Fig. 6 is a section taken on line 6-6 of Fig. 2;

Fig. 7 is a fragmental view showing a modification of Figs. 3 and 4 of a toggle lock design as embodied in my invention;

Fig. 8 is a side view of Fig. 7; and

Fig. 9 is a fragmental detail modification of the view shown in Fig. 7. 7

Referring now to the drawings wherein similar reference characters denote like parts throughout, it will be noted that in a typewriter machine 10 of the usual or conventional type, I show on the carriage mechanism 11 a rack 12 secured to a rack bail frame 13, said carriage having carriage ends 11a as shown in Figs. 2 and 6.

In order to insure locking engagement of said rack ice 2 and the pinion 16 to eliminate the possibility of disengagement skip, and to minimize vibration and jarring, I provide at the top flat surface 26 of the escapement frame or unit 18 which, as shown, is at an incline toward the front of the typewriter 19, an L-shaped post 21. Near the top of said post is a threaded opening for an eccentric or off-center shoulder screw 22 with a threaded end long enough to project through the matching thread opening and to be secured in position when properly adjusted for lock-arm position above rack bail upper surface 13a by a lock nut 22a.

Said shoulder screw 22 when inserted in post 21 is parallel with and disposed directly over the back edge of the carriage rack bail frame 15. Said shoulder screw 22 has attached to it and suspended from it a rack lock arm 23 and is provided with a tension coil spring 24 which is shaped and applied to the lock arm to hold it normally in its forward or locking position, as shown in Fig. 3. Said lock arm 23 is notched at its lower end so that it fits over and behind the rear upper edge of the carriage rack bail frame.

at its other end to rack lock arm 23 to effect a positive cover of notched end 26 over the upper surface of the rack bail frame.

The arm 23 as constructed will insure a positive mesh of the rack 12 and the pinion 16 teeth during the typing operation since the rack, which is secured to the rack bail frme, cannot lift from engagement with the pinion.

In order to allow for the release of the rack by the rack release levers 27 or by the tabulator rack lift lever 35 of the tabulator mechanism, not shown, I provide a' rack lock release cross rod 29 which hangs parallel with and above the top section of the rack bail frame 13, and is secured to end bar members 36 which are in pivotal connection with the rack release lever extension 27a.

It will be noted that said rod is set above the rack bail frame only sufliciently high to allow for its proper lift when unlocked. Its normal position, as shown in Figs. 4 and 6, is just forward of the lower part of the lock arm 23.

Said rod 29 forms the cross member of a hanging ball which as above indicated has the ofiset arms 30 attached which reach upward to and are suspended from around pins or headless screws 31 which act as bearings. It will be noted that these pins 31 also carry spacing collars 31a outside of the bail arms an to give said bail arms working clearance from presently existing mechanisms inside and near the carriage ends, as shown.

Said arms 39 are also provided with openings 34):: as shown for hooking the links 32 thereto. booked at their other ends and are connected in small openings 27b in extensions 27a of the rack release levers 27.

Said release levers as will be seen, ride just outside of the carriage ends 11a, while the extensions 27a are curved downwardly fitting inside existing slots in the carriage ends, said slots having been'enlarged so that the extensions can connect with the rack lock release bail arms 3%, inside of the carriage ends.

Adapted to contact said rod 29 is a claw member 33' which is pivotally mounted onto an extension 34 of the tabulator rack lift lever 35. Said claw 33 is provided Said links are as :claimed.

with a light tensioned retaining spring 36 to normally keep the claw over rod '29 to prevent it from losing'the functioning position with respect to actuating the rack lock release cross rod 29. The rack lift lever. 35 is inconnection with the tabulator mechanism, not shown, and lfunctionsto lift the rack bail frame 13 when the end 38 of the. rack lift lever'35 is operated and moved in thedirection of the lowermostarrow shown in Fig. 4. The pinion '16 is operatively associated with the star wheel36a whose teeth] 37 cooperate with one or more conventional escapement dogs, not shown.

In operation, when one of thera'ck release levers 27 is depressed, it swings in a forward and downward arc. The same happens to its extensions 27a beneathandto the front of the rack lock-releaselbail arms 3! 'Sincefthe 15 extensions 27a are connected .totheupperparts of thel'bail arms'30 by links 32,5a'bove and slightly forward of the bearings 31, when therack releaselever' is depressed, the

lower ends of the bail arms carrying the release *cross'rod 29 are forced rearwardly, and the release rod moves againstt'he rack'lock arm'23 just before'thera'ck lifts, thus releasing the rackfor lift. 'Timing adjustment is made by forming thelinks 32.

'Since the tabulator rack lift lever-35 moves when in operation .in an are opposite to that of the rack release levers and from the ward the lock arm release claw '33, said' claw pulls the rod against the lock arm 231150 free the. rack for lift when the tabulator mechanism is'employed.

In the modification shown in Figs. 7 andfS; it will be noted that I provide a rack "lock 39,w11erein there is 'a rigid arm 40 and a'movable arm .41 pivoted to post 21. Between said arms is a'tension'spring 42'to hold said arms 7 normally together in a locking position. Beneath said armsand in substantially the'same plane thereof are a pair I I of arms 43 and 44 connected pivotally to the'other arms thus forming'a toggle lock-design. j d

' It will befnoted thatsaid arms are'provided'withstopsf 45 and 46 for the arms 'and 41,"re"spectively. Also, arm 43 is provided with a Incl- "47 whereby rod 29 is retained: in position between arms 43 and 44 when the racklock-is' 40 in operation; Furthermore, said arm 43 is provided'with a bifurcatedextension48 accommodating a roller'bearing49 whichnormally rideson the upper surface of the rack bail frame. I

In'Fig. 9 there is shown a further modification of the rack lock assembly with a toggleaction. A post 21a is provided with an L-shaped arm "50 which is fixedthereto.

Pivoted to one-end of'the arm 50 is'a downwardly extending arm 51 pivoted to arm 51a having a bifurcation" 52 accommodating a roller bearing53'for contact on the, 50

uppersurface of rack-bail '13; r

Pivoted to said arm 51a and at the lower end thereof is another arm 54. It will be noted that said arm 54 is thus pivoted at each of its ends to'arms 5t) and '51'a"respec- 'pivots by means-of tension spring 55.

The presently existent back space racklock, not shown, reset for a light contact with the top dffthe release rod29 when back-spacing has been retained merely to act as a:

brake on the carriage back-travel and to prevent overthrow, the rack lock function having been accomplished as-described. a It will be noted that the rack lock post 21 is placed on the top of the escapement frame 18' where the smallcar- .ria'ge roll extension was formerly placed. In addition,'I V have provided a toggle lock forthe rack instead of the rigid lock arrn', as shown in Figs.'3and 5. 7 While preferred embodiments have been illustratedand described, it is to be understood 1that..modifications as to form,:arrangement .andiuse of parts may .be made without-departing.fromthespirit and iscopezof theinvention What I claim is; g a

1. In'atyp'ewritermachine, "a rack 'and'pinion, a post member extending upwardly of the machine, locking means pivoted to the member for contacting said rack, a

tabulator rack lift lever, a claw member pivoted to the' lever, and a rack lock release cross rod operable by'said claw member to release thelocking means upon actuation of the rack lift lever.

2. In a typewriter machine, ap'ostmernben'a'rack lock arm pivotedto thepostimembe'r;arackbail frame, a rack on said frame, apinion for said rack, a rack release lever, a bail arm operable byth'era'ck release lover, a release cross rod in connection with the bail arm adapted to'move against the rack lock arm, a rack lift lever, means on said rack lift lever for actuating the cross rod, and means'for V operating the rack lift lever. 3. A typewriter machine according to claim 2, wherein the rack lock arm is tiltable and adapted to abut against the post memberand hasa recessed lower vportion adapted to swing against the longitudinal ledge o f the rackand against the top-thereof to kelepthe rackv bail frame in;

firmly engaged position with the pinion during operation of the machine.

4. A typewriter machine according to claim 2 wherein said'lockarmton the post is under tension and is provided with hearing .meansfor sliding contactwith the rack bail frame. v

5. .A typewriter-.machine according to claim 2 Where'- in the means .on said rack-{lift lever is a downwardly tensioned clawmember overlapping and contacting the cross rod.

6. .Atypewriter machineaccording to {claim 2 where.-

V in .theracklock arm-is a toggleunit pivoted'from the post i member and is-adapte'dto lock hold the'cross rod.

7. A typewriter machine according'to claim 6 where'- in thetogglennit comprises apair of tensioned upper arm members pivoted to said post and alower pair pivoted to the upper pair and engaging the cross rod, one. of the lower arm members carrying'bean'ng means for sliding contact on the rack bail frame. 7 7

8. In a typewriter machine, an improved locked-inmesh rackiand pinion mechanism, comprising a rack and pinion, apair of spaced depressible rack .release'levers,

a pair of spaced bail arms operable by the levers, a lockrelease crossrod held bysaid bail arms, a rack bail frame beneath .said cross rod, said bail arms forming contact with therack bail frame, a post,v pivotal meansextending from .the posbadaptedto make sliding contact with the rackibail frame, ailift'leve'r, and means operable by the lift lever adapted to engage and actuate the cross rod.

9. An improved mechanism" according to claim' i8," wherein the meansadapted .to engage and actuate the cross rod is mounted on the lift lever. and comprises a pivoted, tensioned, extension member in..the shape of 1a claw member for graspingthe cross rod.

10, In a typewriting machine having a rack and pinion, an improved rackand pinion mesh:l0cking device comprising a post member extending upwardly of the machine, togglelocking :means secured to-the member for contactingsaid rack to holdtherack and pinion inrelatively fixed position, a rack lock release cross rod, and

meansifor actuating the cross :rod to release said toggle locking means. i

. 11. In a typewriting machine ."having carriage ends, :a

rack body and a pinion normallyin mes'h therewith, a, post member, a racklock arm pivoted'to 'the post mem- 'movethe rod against the.rack'lockarm,a pair of rackrelease levers, extensions to said rack release levers "connected .to saidzrackllockrelease bail .arms for actuation of the .rack lock "release bail .arms and rod, a tabulator rack lifting deviceandan extending member on thetabu lator rack lifting device for actuation of the rack lock release cross rod.

12. A typewriting machine according to claim 11 wherein the rack lock arm is a toggle unit secured to the post member and adapted to retain the rack lock release cross rod.

13. A typewriting machine according to claim 12, wherein the toggle unit comprises a pair of coil spring connected upper arm members, one of which is rigidly and one pivotally secured to the post member, and a lower pair pivoted to the upper pair and retaining the cross rod, one of the lower arm members carrying bearing means for sliding contact on the upper surface of the rack body.

14. In a typewriting machine having a toggle lock and a rack and pinion locked in mesh thereby, said toggle lock including lower toggle arms, a pair of spaced depressible rack release levers with added extensions, a pair of spaced bail arms, hooked heavy wire links connecting said rack release lever extensions with the bail arms, and a lock release cross rod held normally by said bail arms in light contact with the inner edges of the lower toggle arms, said light contact being obtained by centering said cross rod between said lower toggle arms and by the formation of said hooked heavy wire links connecting said rack release lever extensions with the bail arms, the toggle lock of the rack being released by actuation of said cross rod.

Murphy Aug. 18, 1885 Price June 20, 1899 

